Progressives in the Democratic Party are outraged after 13 Democrats voted against an amendment that would have allowed Americans to buy cheaper prescription drugs from Canada, saying it’s a sign that Big Pharma has too much power in the party.

The amendment was unlikely to pass, but critics say that’s why it should have been a safe way for Democrats to show their support for combating high drug prices.

Large majorities of Americans think that prescription drug prices are too high, and support measures to lower them. A Kaiser Family Foundation poll from last September found that 71 percent supported importation of medicines from Canada.

The amendment, drafted by Sens. Bernie Sanders of Vermont and Amy Klobuchar of Minnesota, would “establish a deficit-neutral reserve fund relating to lower prescription drug prices for Americans by importing drugs from Canada.” It would have amended the Senate budget resolution passed early Thursday morning that brings Obamacare a step closer to being repealed.

It’s not a radical idea to import medication from Canada, where they pay a lot less for the exact same drugs. 72% of Americans support it. pic.twitter.com/m5kzJEI3iw

Progressives vented their anger on social media, focusing particular ire on Sen. Cory Booker, who only hours earlier had positioned himself as a progressive fighter by becoming the first senator to testify against a sitting colleague at Republican Sen. Jeff Sessions’ confirmation hearing to be attorney general in the incoming Donald Trump administration.

We have to hold our own reps accountable as well. See which Democratic Senators voted no on importing cheaper prescription drugs from Canada https://t.co/xvAKldx90A

Booker said in an emailed statement that he supported the importation of prescription drugs to control costs generally, but that this amendment didn’t adequately make sure foreign drugs meet American safety standards.

“I support the importation of prescription drugs as a key part of a strategy to help control the skyrocketing cost of medications. Any plan to allow the importation of prescription medications should also include consumer protections that ensure foreign drugs meet American safety standards. I opposed an amendment put forward last night that didn’t meet this test. The rising cost of medications is a life-and-death issue for millions of Americans, which is why I also voted for amendments last night that bring drug prices down and protect Medicare’s prescription drug benefit. I’m committed to finding solutions that allow for prescription drug importation with adequate safety standards.”

He also defended his vote on Twitter:

.@LaurenLovesWI I unequivocally support drug imports to lower cost but plan must include protections so foreign drugs meet safety standards.